1. Field of the Invention
The present invention relates to a sheet package producing system, a sheet handling device, and a fillet folding device. More particularly, the present invention relates to a sheet package producing system, a sheet handling device, and a fillet folding device in which efficiency in producing a sheet package can be high, and also which is compatible to plural types of sheet-shaped products.
2. Description Related to the Prior Art
X-ray films are included in various recording sheets or any sheet-shaped products. Plural sheets are stacked together, and packaged and shipped in a form of sheet package. To obtain the X-ray films, web having a great width is slitted into continuous sheet material having a width of the X-ray films. Then the continuous sheet material is unwound from a roll, and cut into the sheets. The sheets are stacked in a predetermined number. A protective cover is placed on the sheets to obtain a cover-fitted sheet stack in which the protective cover protects the sheets from damages or scratches. The cover-fitted sheet stack is inserted into and enclosed tightly in a packaging bag with light-tightness. The packaging bag with the sheet package is inserted in a decorative box, and shipped.
Although plural types of the X-ray films exist, the total number of the available types is not very high. A system for producing the sheet package of the X-ray films is designed in a manner specialized for one particular type or size of the X-ray films. A known example of control of the producing system is a central processing type, according to which a central control device includes one CPU, and plural controllers connected with the CPU and with plural component devices in the producing system. The central control device effects overall control of the producing system. One advantage of the central processing type of control consists in considerable highness in the communication speed, because the controllers are connected with the CPU by means of direction connection between circuit boards.
The central processing type has problems in difficulty in modifying the system, and in lack of suitability for easy inspection and maintenance. As disclosed in JP-B 2506244 (corresponding to JP-A 5-053620), a distributed processing type of control is known in contrast with the central processing type of the control. According to the distributed processing control in the prior document, the system is constituted by plural component devices, which include respectively CPUs for control of the component devices. Signals or control information is sent and received between the CPUs, the control information including information of completion of the processing, and results of the processing. The component devices are interconnected by the general-purpose interface such as SCSI and RS232C, which are used for communication between the CPUs. Control programs are designed for the respective component devices. Thus, each program can have a small scale, and can be modified easily if desired.
However, there is a problem in that the amount of control information to be sent and received is considerably high between the CPUs, because the plural CPUs are operated for overall control of the producing system. The interface of a general-purpose type is used in sending of the control information between the CPUs, and has a problem in low speed of communication. The processing speed of the producing system cannot be high because of the low communication speed. Among the producing steps, steps of handling sheets or parts requires high speed for the purpose of efficiency. However, the low communication speed is inconsistent to improvement in efficiency.
There are a number of known sheet handling devices for use with the sheets or a sheet stack which should not be handled with extreme pressure. U.S. Pat. No. 5,365,817 (corresponding to JP-A 5-169396) discloses a use of a vacuum chamber with which surplus air in the sheet stack is ejected. Also, U.S. Pat. No. 5,352,085 (corresponding to JP-A 7-144778) discloses a conveyor device for feeding the sheet stack between plural stations. The conveyor device includes at least three conveyor mechanisms connected in series. Among the conveyor mechanisms, a first one is inclined upwards. A second one is oriented horizontally. A third one is inclined downwards. The first is disposed to extend to a position under some of a plurality of the sheet stacks. All of the conveyor mechanisms are driven to feed some of the sheet stacks to an upper position of the conveyor device. After this, the conveyor device is transferred to the vicinity of a supply position. Again, the conveyor mechanisms are actuated, to feed the sheet stack to the supply position.
However, the device of U.S. Pat. No. 5,365,817 has a shortcoming in that time for the operation is considerably long to lower the speed, because the vacuum chamber must operate by keeping the sheet stack separate from external air. Also, the device of U.S. Pat. No. 5,352,085 has a problem in that the conveyor device has a considerably large size, and has a complicated structure, and raises the manufacturing cost. If the speed of driving the conveyor mechanisms is set very high, downfall or disorder is likely to occur in the train of the plurality of the sheet stacks. The device is unsuitable for raising the efficiency.
JP-A 2001-080609 discloses an example of fillet folding device for use with a packaging bag to fold front and rear fillets. In a process of packaging the cover-fitted sheet stack or sheet stack, a bag material for forming a bag body is supplied. At first, a corner positioning plate is set in a bending position of the front fillet, and keeps the cover-fitted sheet stack or sheet stack stationary in the bag body. Then the rear fillet is bent back and folded to lie on the outside of the bag body. After this, the front fillet, which is defined between a front edge and the bending position, is moved up at a predetermined height. The corner positioning plate is moved away, before the front fillet is bent back and caused to overlap on the rear fillet. Finally, a sticker is provided, and attaches the front edge of the front fillet to the rear fillet.
However, the plural types of the X-ray films exist, and are different in the size. Accordingly, the area and shape of the bag body, and the size of the front and rear fillets are different between the types of the X-ray films according to the size. In the above-described device of the prior art, an amount of protruding a movable rod is predetermined and invariable. An amount of sliding of a cylinder is also invariable. Thus, the device is not compatible to the plural types between which the sheet size is different. Also, a problem arises in that the known device cannot produce a sheet package in which the sizes of the front and rear fillets are changed if desired.